Purpose

Artifacts caused by metallic implants remain a challenge in computed tomography (CT). We investigated the impact of photon-counting detector computed tomography (PCD-CT) for artifact reduction in patients with orthopedic implants with respect to image quality and diagnostic confidence using different artifact reduction approaches.

Material and methods

In this prospective study, consecutive patients with orthopedic implants underwent PCD-CT imaging of the implant area. Four series were reconstructed for each patient (clinical standard reconstruction [PCD-CT_Std], monoenergetic images at 140 keV [PCD-CT_140keV], iterative metal artifact reduction (iMAR) corrected [PCD-CT_iMAR], combination of iMAR and 140 keV monoenergetic [PCD-CT_140keV+iMAR]). Subsequently, three radiologists evaluated the reconstructions in a random and blinded manner for image quality, artifact severity, anatomy delineation (adjacent and distant), and diagnostic confidence using a 5-point Likert scale (5 = excellent). In addition, the coefficient of variation [CV] and the relative quantitative artifact reduction potential were obtained as objective measures.

Results

We enrolled 39 patients with a mean age of 67.3 ± 13.2 years (51%; n = 20 male) and a mean BMI of 26.1 ± 4 kg/m². All image quality measures and diagnostic confidence were significantly higher for the iMAR vs. non-iMAR reconstructions (all p < 0.001). No significant effect of the different artifact reduction approaches on CV was observed (p = 0.26). The quantitative analysis indicated the most effective artifact reduction for the iMAR reconstructions, which was higher than PCD-CT_140keV (p < 0.001).

Conclusion

PCD-CT allows for effective metal artifact reduction in patients with orthopedic implants, resulting in superior image quality and diagnostic confidence with the potential to improve patient management and clinical decision making.

中文翻译：

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用于减少金属伪影的光子计数探测器计算机断层扫描：骨科植入物患者不同伪影减少技术的比较研究

目的

金属植入物引起的伪影仍然是计算机断层扫描 (CT) 中的一个挑战。我们使用不同的伪影减少方法，研究了光子计数探测器计算机断层扫描 (PCD-CT) 对减少骨科植入患者的伪影对图像质量和诊断置信度的影响。

材料与方法

在这项前瞻性研究中，连续接受骨科植入物的患者对植入物区域进行了 PCD-CT 成像。为每位患者重建四个系列（临床标准重建 [PCD-CT _Std ]、140 keV 的单能图像 [PCD-CT _140keV ]、迭代金属伪影减少 (iMAR) 校正 [PCD-CT _iMAR ]、iMAR 和 140 的组合keV 单能 [PCD-CT _140keV+iMAR ]）。随后，三名放射科医生以随机和盲法的方式评估了重建的图像质量、伪影严重程度、解剖轮廓（邻近和远处）以及使用 5 点李克特量表（5 = 优秀）的诊断置信度。此外，还获得了变异系数 [CV] 和相对定量伪影减少潜力作为客观指标。

结果

我们招募了 39 名患者，平均年龄为 67.3 ± 13.2 岁（51%；n = 20 名男性），平均 BMI 为 26.1 ± 4 kg/m ²。 iMAR 重建的所有图像质量测量和诊断置信度均显着高于非 iMAR 重建（所有p  < 0.001）。没有观察到不同伪影减少方法对 CV 的显着影响 ( p  = 0.26)。定量分析表明 iMAR 重建的伪影减少最有效，高于 PCD-CT _140keV ( p  < 0.001)。

结论

PCD-CT 可以有效减少骨科植入物患者的金属伪影，从而获得卓越的图像质量和诊断信心，并有可能改善患者管理和临床决策。